Steam-engine valve



UNITED STATES PATENT OFFICE.

CHARLES RUMLEY, OF ROCHESTER, NEW YORK.

STEAM-ENGINE VALVE.

Specification of Letters Patent No. 11,908, dated November 7, 1854.

To all whom t may concern:

Be it known that I, CHARLES RUMLEY, of Rochester, in the county ofMonroe and State of New York, have invented certain new and usefulImprovements in Steam-Engine Valves, of which the following is a full,clear, and exact description, reference being had to the accompanyingdrawings of the same, which make part of this specification, and inwhich- Figure l represents a side elevation of a rotary steam engine,having the heads of the cylinder and steam chest removed to show moreclearly the interior part-s; Fig. 2 represents a. vertical section takenthrough the axis of the cylinder, and steam chest, and Figs. 3, 4, 5, 6,7 Aand 8 represent the valve, and its movable part in various positions.

The cylinder (A) as represented in the accompanying drawings is of theusual diameter and length, and is fitted with two ports (B and B) eitherof which will admit steam to, or exhaust it from the cylinder, but whenone is used to admit the steam, the other is invariably used to exhaustit. The conversion of the ports at will from admission to exhaust, andvice versa, admits of the motion of the engine being reversed. Thischange is readily effected by a simple adjustment of the valve.

The steam chest (C) which contains the valves, is p-laced on the side ofthe cylinder and connects with the ports by the side pipes (D). Twopassages (E E) connect the valve chamber' with the side pipes, andanother passage (F) connects this chamber with the exhaust pipe (Gr).The side (H) of the chamber through which these passages enter is madeperfectly plain, and smooth, and is fitted with an adjustable plate (I)and a self adjusting plate (J) which together form a seat for -therevolving valve (K) to slide against, to admit and cutoff the steam.

The adjustable element of the valve seat, consists of a plate (I) withboth sides perfectly plain and parallel. This plate is nearly a semicircle, and is mounted upon the inner end of a tubular spindle (L) whichpasses to the outside of the valve chest, where it has a hand leverattached to it, by which it can be turned to the right or left farenough to -uncover one of the passages to the side pipe and cover theother, as the engine is required to turn to the right or left; ybyturning the hand lever to a point into the atmosphere.

half way between these two extremes, the plate will cover both thepassages to the steam pipes, and shut olf the steam from the cylinder.The side of `this plate next the side of the chamber, in `which thesteam and exhaust passages are, has a cavity (a) in it like that in theordinary D slide valve to connect the passage which communicates withthe exhaust side pipe with the passage which conducts the exhaust steamWhen the engine is stopped, this adjustable plate occupies the positionshown in Fig. I; when the engine is required to turn in one direction,it occu` pies the position shown in Fig. 3, and when it is required toturn in the reverse direction, the plate is set as represented in Fig.4. This plate with its hollow axle, are shown in perspective in Fig. 8.

The self adjusting plate (J) is smaller than the adjustable plate, beingonly about 459 of a circle. It is the same thickness as the other plate,and finished in like manner. It is mounted'upon the middle of a solidspindle (M) which extends through the axis of the hollow spindle (L) onwhich the other plate is mounted at` one end, and through the hollowaxis of a rotatin valve (K) at the other end. The end of this spindle isfitted with an arm (N) which connectsthrough the medium of a link rod,with the slide of a governor, so thatwhen the speed of the engine`decreases, the arm will be raised, and when the speed increases, thearm will descend. The effect of this operation of the governor upon thearm, will be f to cause the edge (b) ofthe self adjusting plate toapproach that ofthe adjustable plate when the speed increases, and torecede therefrom as the speed diminishes. This self adjusting plate isseen at its extreme point of recession in Fig. 6, and at an intermediatepoint in Fig. 5. Those variations in the position of this self adjustingplate are designed to affect `in a corresponding manner, the point atwhich the steam is cut olf, and the proportion in which it is allowed toexpand, and this is effected in a manner which will be presentlyexplained.

Between the adjustable and self adjustin parts of the valve seat, andthe head (O) o the steam chest, a plate valve (K) with two i wings, eachabout 60 of a circle, is arranged to rotate. The side of this Valvewhich slides against the seat plates (I and J) is perfectly plain andsmooth, and at right angles to its axis kot rotation. This -Valve ismounted upon a hub that turns upon the spindle (M) which carries theself adjusting seat plate (J). This hub alsopasses through a stuffedjoint in the head (O) of the chest. Motion is comnnmicatedl by gear fromthe axis of. the piston to this hub,so that the valve (K) andthe pistonwill revolve isochronally.

From an inspe-ction'of the relative position of the several parts' ofthe valveV and chest, already described, it is plain that the steam canonly pass into the aperture communicating with the side pipe', byentering the space (Q) Fig. 7 between/the adjustable and self adjustingplates of the valve seat; now, as the valve rotates inthe contrarydirection from the piston and in equal time, and its kwings will coverabout 1009er a circle, and the back edgeol-the wing admits the steam,and the front, cuts it olf, the steam-can be 'readily cuty ott' ywhenthe piston has made a greater orless proportion of the; stroke.;v I f fv 'Whenarra'ngedto outl oli at two ythirds stroke the self adjusting'portion ofthe valve seat (J) is shown "in the position at which thistakes place invFig. 5,` and in that in which it cu'tsjoif'at full strokein'lFig. 6. When the velocity increases, indicating an excessofsteaIm-the'arm (N) raises by the` action or'V thegovernor, anddepressesthe part of the seat (J) connected with it,l which causesthesteam to be cutoli sooner;l -and when thevspeed decreases, indicating`a deciency of steam,fthe arm (1N) descends, the plate J)rises,more'steam is `admitted into the cylinder,fand the speed therebyaccelerated. From this method-of operation it is obvious, the'velocityof the engine 'cannot be much' varied with any ordinaryvariation of duty. As the governor'as well as the steam chest areconstructedjin the ordinary manner, I do not deem/ af particulardescription of them necessary. The cylinder is not bored out trulycylindrical, but its inner'periphery is/composed of alittle more than1800 'of' eachof two.v intersecting circles, whose radii are-equal, andwhose centers are atha distance corresponding to the difference betweenthe extreme radii of the curves in which the segmental periphery (R) ofthe piston works, in the different parts of its revolution.

The pistonv consists of a cylindrical hub (s) which equals Ain lengththe interior of 'the cylinder, and its diameter equals two thirdsorthereabouts that` of the cylinder; and a radial slide (T) which movesfreely across the axis of this hub, each end Vof the slide being ittedwith av hinged foot (R) whose outside is 'of thesame curvature as theinterior of the cylinder. This hub is fitted` at each end' with agudgeon which passes through stuffed bearings in the" head (U) of thecylinder. Thebearings of these gudgeons are eccentric to the axis of thecylinder so far as to bring the periphery of vthe'hub in contact withone side of the cylinder. The joints between the slide and hub, andbetween the ends of the hub, and heads of the cylinder, are well packedin the usual or in any convenient and approved manner. The side of thecylinder, too, against which the hub bears should be fitted witharemo-vable stave of gun metal, lwhich can be adjusted to vcompensatefor wear.

The bore of the cylinder as represented in the drawing, does not-conformstrictly in its shape to the geometrical denition of thev term`cylinder, 'as it is in strictness an ellipse approximating very Vnearlyto a cylinder.V yIts-long .diameter is 55,5@ inches, and its shortdiameter is 5 inches, andthe `radii of the curves of everypart of `itare equal,

its -configuration being produced byl sweeping it with equal radii fromthree vcenters (m m2) iny a line with the long axis, the outer' centers(w1 m2) or foci being eachfinch from the inner center (0b.). A cylinderof' this form and proportions is adapted toca piston constructed,jointed, and arranged in the manner represented in the drawing. j'

f ff the joints wereplaced at a greater or .less"di`stance fromthev4ends of the piston,

the maximum deflection from the ends from the line of the slide-ofthepiston would be greater or less, and ythis would involve a correspondingchange in the* foci'of the curves of'the cylinder, as the various lineswhich `the radii of the' end of the piston assumed vmust all converge toa4 common focus, since these piston ends always stand perpendicular'tothe curves swept from the foci, while sliding over the same.

'In practice, the cylinders are constructed byboringthem on two centersin succession which coincide withr the two foci of the ends. Toperfect'the cylinder according to theory, it should be boredgon' a thirdcenter equidistant from, and kin a line withthe two foci; but as thefoci are so .near together, this'is unnecessary, and for lall practicalpurposes doubleboring` is sufficient. The precise positions. of thesereciproca-lly eccentricl centers -on which the ,cylinder is bored willbe varied bythe position of the joints in the slide, and ycan only bedetermined by careful calculation when the structure, and all thedimensions of the different parts are known. 'But by the rule abovegiven, these calculations can be madewith great facility and certainty.Whenv the cylinder has been bored in one center, that gives the propershape toone side, Vthen the axis of the boring instrument is made tocoincide wit-h the other center, and the other sideyis bored oi?k theproper shape. 'In Fig. l, the'black lines show the finished cylinder asbored on two centers, and the valve, revolving isochronally with thepis- 10 red lines the interior of the cylinder preton substantially asherein set forth. vious to boring. In testimony whereof, I have hereuntoHaving thus described my invention what subscribed my name.

I claim therein as new and desire to secure by Letters Patent is CHARLESRUMLEY' The combination of the compound valve- Witnesses:

seat consisting of an adjustable, and a self A. B. CHILDS,

adjusting segment, With a rotating Wing I. H. WATSON.

